Irradiation synthesis of sulfonyl vinylamines



United States Patent 0,

This invention relates to, and has as its principal object provision of, a new process for synthesizing certain ethylenically-unsaturated amines having a sulfone group.

Ethylenically-unsaturated compounds are an important class of organic materials that have found widespread use due to the reactivity of the carbon-to-carbon double bond. I

Thus, the vinyl compounds are of considerable commercial importance for the preparation of polymeric materials by self-addition to the double bond. A further type of valuable reaction possible to such compounds is the addition of other elements or compounds to the ethylenic double bond.

The present invention provides a process in which certain ethylenically-unsaturated sulfonamides are molecularly rearranged to yield sulfonylvinylimines. More specifically, N-hydrocarbo-Z-hydrocarbosulfonylvinylamines are obtained by rearrangement of the corresponding N- vinylsulfonamides under the influence of substantial amounts of ionizing radiation according to the equation:

ionizing RSOgNOH:CHz 1]{ radiation wherein R and R are hydrocarbon radicals of generally not more than 12 carbons each and are preferably alkyl or aryl. The compounds obtained can be referred to as 1-hydrocarboamino-2-hydrocarbosulfonylethylenes as well as N-hydrocarbo-2-hydrocarbosulfonylvinylamines.

In the general formula of the products obtained,

- R and R are hydrocarbon radicals free from open chain.

unsaturation with not more than 12 carbons each, i.e.,

1-12 carbon atoms, and may be either the same or difbons. Examples of the hydrocarbon radicals that are em-v braced include methyl, ethyl, butyl, hexyl, cyclohexyl, phenyl, tolyl, naphthyl, and diphenyl for R and R.

Examples of compounds included in the N-hydrocarbo- Z-hydrocarbosulfonylvinylamines of the invention are, in addition to those described elsewhere in this specification, N-phenyl-Z-phenylsulfonylvinylamine, N-n-butyl-Z- n-butylsulfonylvinylamine, N cyclohexyl-Z-o-tdlylsulfonylvinylamine, N ethyl-2-p-tert. butylphenylsulfonylvinylamine, and N-n-hexyl-2-phenylsulfonylvinylamine.

The N-vinylsulfonamides utilized as starting materials in the invention are readily available trom the reaction of acetylene with sulfonamides, according to US. 2,317,- 804, 2,324,896, and Cairns and Sauer, J. Org. Chem. 20, 627 (1955). Suitable N-vinylsulionamides that can be employed include N-ethyl-N-vinyl-p-tert.butylphenylsulionamide, N-n-butyl-N-vinyl-n-butanesulionamide, N-cyclohexyl-N-vinyl-o-toluenesulfonamide, and N n hexyl- N-vinylbenzenesulfonamide.

The ionizing radiation utilized now to bring about the rearrangement of the N-vinylsulfonamides includes both radiation in the form sometimes regarded as particle radiation and radiation in the form sometimes re-' garded as ionizing electromagnetic radiation.

By particle radiation is meant an emission of accelerated electrons or nuclear particles such as protons, neu-;,

trons, alpha-particles, deuterons, beta-particles, or the not give efiective rearrangement.

2,988,493 Patented June 13, 1961 like, so that the said particle impinges upon the sulfonamide. The charged particles can be accelerated by means'of a suitable voltage gradient, using such devices as a cathode ray tube, resonant cavity accelerator, a Van de Graalf accelerator, a betatron, a synchrotron, a cyclotron, or the, like, as is well known to those skilled in the art. Neutron radiation can be produced by suitable nuclear reactions, e.g., bombardment of selected light metal (beryllium) targets with deuterons or alpha-particles. In addition, particle radiation suitable for carrying out the process of the invention can be obtained from an atomic pile, or from radioactive isotopes or from other natural or artificial radioactive materials.

By ionizing electromagnetic radiation is meant radiation of the type produced when a metal target (e.g., gold or tungsten) is bombarded by electrons possessing appropriate energy. Such radiation is conventionally termed X-ray. In addition to X-rays produced as indicated above, ionizing electromagnetic radiation suitable for carrying out the process of the invention can be obtained from a nuclear reactor (pile) or from natural or artificial radioactive material. In these latter cases the radiation is conventionally termed gamma rays.

It is recognized that the energy characteristics of one form of ionizing radiation can be expressed in terms which are appropriate for another form. Thus, one may express the energy of either the particles of radiation commonly considered as particle radiation or of the photons of radiation commonly considered as wave or electromagnetic radiation in electron volts (e.v.) or million electron volts (mev.). In the irradiation process of this invention, radiation consisting of particles or photons having an energy of 0.1 mev. and over is preferred. With radiation of this type, rearrangement of the vinylsulfonamides can be obtained from the crystalline materials with a minimum length of exposure to the radiation, permitting maximum efliciency in utilization of the radiation. Particles or photons with an energy of 0.5-4 mev. are the most useful from a practical standpoint.

'A minimum exposure of at least 0.1 watt-sec./cm. of surf-ace is necessary since lower degrees of exposure do The rate of rearrangement per unit of absorbed energy usually increases with decreasing beam intensity. Exposures as high as 1000 to 10,000 watt-sec./cm. may be employed. The exposure may be carried out in one slow pass or in several faster ones and may be conducted at any convenient rate of energy input.

The rearrangement of this invention is carried out preferably in the solid phase although the liquid phase can be used. A temperature of about 0-50 C. is usable with room temperature preferred. Pressures are not important solubility in organic solvents, and ultraviolet absorption maxima at longer wave lengths than the corresponding vinylsulfonamides.

The new compounds dilfer also in chemical properties Mild acid hydrolysis, for example, converts them to sulfonylacetaldehydes.

The following examples, in which parts are by weight, further illustrate specific embodiments of this invention. In the absorption data given, A is the wave length, e the molecular extinction coefiicient, and k the specific extinction coefiicient as defined by Harrison, Lord and Loo'fbourow, Practical Spectroscopy, Prentice-Hall, N.Y. (1948), pages 363-365. EtOH represents ethanol.

EXAMPLE 1 N-methyI-Z-phenykulforiylvihylamine N-methyl N vinylbenzenesu'lfonaniide (40 g.) was placed in a crystallizing dish 12 cm. in diameter. The dish was covered with 0.25-mil Mylar polyester'film and set in an ice bath. The N methyl-N-vinylbenzenesulfonamide [M.P. 34-35 0., xgge=242 m (e=6l00)] was prepared by condensing N-methylbenzenesulfonamide with acetylene as described by Cairns and Sauer, loc. cit. The N-rnethylN-vinylbenzenesulfonamide was exposed to a beam of Z-mev. electrons from a Van de Graaflf accelerator for 66 seconds in sixty 1.1-second exposures. The electronic energy incident on the surface of the sulfonamide was 660 watt-sec./cm.

The irradiated material, a mixture of solid and gum, was dissolved in 40 ml. of boiling ethyl acetate. Cooling the ethyl acetate solution to C. caused the precipitation of 15.8 g. of N-methyl-Z-phenylsulfonylvinylamine. After recrystallization from ethyl acetate the N-methyl-Z- phenylsulfonylvinylamine melted at 129130 C.,

33 263 mp e Its infrared absorption spectrum contained a strong band at 2.95 t indicative of an N--H bond.

Analysis..Calcd. for C H NO S: C, 54.8; H, 5.6; mol. wt., 197. Found: C, 54.7; H, 5.5; mol. wt., in boiling acetone, 211.

The Z-sulfonylvinylamine dissolved in cold 2 N hydrochloric acid with formation of methylamine and phenylsulfonylacetaldehyde. The phenysulfonylacetaldehyde reacted with 2,4-dinitrophenylhydrazine to give-phenylsulfonylacetaldehyde 2,4-dinitrophenylhydrazone. The melting point (172-17 5 C.) ultraviolet spectrum and infrared spectrum of the phenylsulfonylacetaldehyde 2,4-dinitrophenylhydrazone were identical with those of an authentic sample made by condensing sodium phenyl mercaptide with the ethyl acetal of chloroacetaldehyde, oxidizing the resultant product with hydrogen peroxide in .acetic acid to the ethyl acetal of phenylsulfonylacetaldehyde, and treating the latter with 2,4-dinitrophenylhydrazine dissolved in 2 N hydrochloric acid.

Analysis.-Calcd. for C H N O S: C, 46.1; H, 3.3; S, 8.8; N, 15.3. Found: C, 45.9; H, 3.4; 8,8.6; N, 15.3.

EXAMPLE 2 N-methyl-Z-phenylsulfonylvinylamine Crystalline N-methyl-N-vinylbenzenesulfonamide (100 parts) at C. was exposed to an X-ray beam for 225 minutes. Dosimetry measurements with aqueous ferrous sulfate by the method of Weiss, Nucleonics 10, No. 7, 28 (l952),showed that energy from the X-ray beam" was absorbed in the sample at a rate of 7200 rads per minute. Infrared analysis showed that the irradiated sulfonamide contained 25 parts (25% yield) of N-methyl-Z-phenylsulfonylvinylamine.

A series of experiments was run under the same conditions except that the temperature, exposure time and state 'as in'Example 1.

.4 of the sample (solid, liquid or super-cooled liquid) were varied. The results are shown in the table.

TABLE .REARRANGEMENT OF N-METHYL-N-VINYLBEN- Z E N E S U L F O NAMID E TO N-METHYL-Z-PHENYLSUL- FONYLVINYLAMINE BY X-RAYS Exposure Yield, Temp., 0. Time, State Percent Min.

1 Super-cooled liquid.

EXAMPLE 3 N-methyl-2-p-t0lylsulf0nylviny[amine N-methyl-N-vinyl-ptoluenesulfonamide (6.66 g.) was placed in a crystallizing dish 5.5 cm. in diameter and exposed to 440 watt-sec./cm. of 2-mev. electrons at 25 C. as in Example 1. Nmethyl-N-vinyl-ptoluenesulfonamide was prepared from N-methyl-p-toluenesulfonamide and acetylene by the method of Cairns and Sauer, loc. cit. Crystallization of the reaction mixture from ethyl acetate gave 4.77 g. of N-methyl-Z-p-tolylsulfonylvinylamine The infrared absorption spectrum had a strong NH band at 2.95 4.

Ana'lysis.Calcd. for C H N OS: C, 56.9; H, 6.2; N, 6.6; S, 15.2. Found: C, 57.0; H, 6.2; N, 6.7; S, 15.3.

Treatment of N-methyl-2-p-tolylsulfonylvinylamine with a hot solution of 2,4-dinitrophenylhydrazine in aqueous ethanol containing hydrochloric acid gave ptolylsulfonylacetaldehyde 2,4 dinitrophenylhydrazone, M.P. 184-186 C.

Analysis.--Calcd. for C H N O S: C, 47.6; H, 3.7; N, 14.8; S, 8.5. Found: C, 47.8; H, 3.7; N, 14.3; S, 8.3.

EXAMPLE 4 N-methyl-Z-p-tolylsulfonylvinylamine N-methyl-N-vinyl-p-toluenesulfonamide parts) 'was exposed to an X-ray beam at 25 C. for 77 minutes.

Ferrous sulfate dosimetry showed that X-ray energy was absorbed in the sample at a rate of 6800 rads/min. The irradiated sulfonamide contained 13 parts of N- methyl-2-ptolylsulfonylvinylamine. In experiments that were identical except for the temperature, 5 parts of the vinylamine was formed at 81 C. and 6 parts was formed at 76 C.

EXAMPLE 5 N-n-butyl-Z-p-tolylsulfonylvinylamine N-nbutyl-N-vinyl-p-toluenesulfonamide [B.P.=126/0-1 mm.; n =1.5279,' k2=242 m (e=7340)] was prepared from N-butyl-p-toluenesulfonamide and acetylene by the method of Cairns and Sauer, loc. cit. N-n-butyl-N-vinyl-ptoluenesulfonamide (1.0 g.) was placed in a crystallizing dish 2.0 cm. in diameter and exposed to 660 watt-sec./cm. of 2-mev. electrons, at 25 The infrared absorption spectrum of indicating that rearrangement to N-methyl-Z-n-butylsulactionamixture had' a strong at 2.95 1,

and

r kff= 267mfi (k- 45') M u ent of 198- parts of product. w'ith .=a hot solu tiodof 2,4-dinitrophenylhydrazin'e in aqueous ethanol containing-hydrochloric acid gave 200 parts of p-tolylsulfonylacetaldehyde2,4-dinitrophenylhydrazone, ,M.P.=

184-186."."CL The 'yield of the rearrangement product,

fonylvinylamine had occurred.

Alkaline hydrolysis and quantitative determination of the liberated methylamineshowed that the reaction mixture contained 13.4% by weight of N-methyl-Z-n-butylsulfonylvinylamine.

EXAMPLE 7 N-methyl-2-methylsulfonylvinylamine N-methyl-N-vinylmethanesulfonamide (1.0 g.) was placed in acrystalli'zing dish2.0c'm. in diameter and exposed to 1980 watt-secJcm. of 2-mev. electrons. Analysis of the irradiated sulfonamide showed that it contained 9.3% by weight of N-methyl-Z-methylsulfonylvinylamine.

EXAMPLE 8 N-methyI-Z- S-naphthylsulfonylvinylamine N-methyl-N-vinyl-p-naphthalenesulfonamide was prepared by treating the p-toluenesulfonic acid ester of N methyl-N-(2-hydroxyethyl)-fl-naphthalenesulfonamide with alcoholic potassium hydroxide. Ten grams of the ester was refluxed for 2 hours with a solution of 5 grams potassium hydroxide in 50 ml. of 95% ethanol. The reaction mixture was diluted with 50 ml. water and extracted with ether. The ether was removed by vacuum evaporation and the N-methyl-N-vinyl-fl-naphthalenesulfonamide distilled through a short path distillation apparatus. The fraction (3.3 grams) boiling at 150-160 C./0.05 mm. as collected.

Analysis.Calcd. for C H SO N: C, 63.2; H, 5.26; N, 5.67. Found: C, 63.36; H, 5.37; N, 5.85.

The structure of the product was further confirmed by its infrared spectrum.

N methyl N-vinyl-fl-naphthalenesulfonamide (0.47

1 gram) was placed in an open crystallizing dish 2.0 cm.

in diameter and exposed to 660 watt-sec./cm. of 2-mev. electrons at 25 C. The viscous product was taken up in hot methanol. Cooling the methanol solution caused the precipitation of 0.04 gram of N-methyl-Z-fi-naphthylsulfonylvinylamine (M.P.==134-136 C.).

Analysis.--Calcd. for C H SO N: N, 5.67. Found: N, 5.77.

EXAMPLE 9 N -mathyl-2-phenylsulfonylvinylamine A solution of 250 parts of N-methyl-N-vinyl-benzenesulfonamide and 1000 parts by volume of methanol was placed in an ice bath and exposed to a beam of Z-mev.

' ,N methyl-fl-p-tolylsulfonyl-a-styrylamine N methyl N arstyryl-p-toluenesulfonamide (0.5 g.) was placed in a small open crystallizing dish of cross section 3.14 cm andlexposed to 550 watt-sec/cm? of 2- mev. electrons at 4060 C. A portion of the viscous product was, dissolved in hot ethyl acetate. On cooling, white crystalline N 4 methyl B p-tolylsulfonyl-a-styrylae mine precipitated, M.P.105-106" C. 3 v

' Anizlysis.-'Calcd. for C H SO N: C, 66.88; H, 5.96. Found: C, 67.03; H, 6.33.

The structu're of'the product was further established by its infrared spectrum and its ultraviolet spectrum The yield of N-methyl-B-p-tolylsulfonyl-a-styrylamine wasfoun'd tov be by hydrolysis of a portion of the crude reaction product with 5% sodium hydroxide and titration of liberated methylamine. I

' The N methyl -N a-styryl-p-toulenesulfonamide was prepared as follows: A solution of 57 grams of prtoluenesulfonyl chloride in 150 ml. of pyridine was added slowly to a solution of 15 grams of cc-N-methyl-aminophenylethanol in 125 mlj of pyridine, while the temperature was maintained at 40-45 C. The mixture was poured into a mixture of ice and hydrochloric acid and extracted with benzene. The crystalline N-met hyl-N-ptolylsulfonyl-2-amino-Z-phenethyl-p-toluenesulfonate (22 grams, M.P. 103-l04 C.) obtained on evaporating the dried benzene extract wasrefluxed for 2.5 hours with a solution of 6 grams of potassium hydroxide in 75 ml. of alcohol. The cooled reaction mixture was slurried with ml. of water and filtered to give 10.2 grams of crystalline N methyl N a-styryl-p-toluenesulfonamide (M.P. 82-83 C.).

A'malysis.Calcd. for C H SO N: C, 66.88; H, 5.96. Found: C, 66.95; H, 6.25.

The structure of the compound was further confirmed by its ultraviolet spectrum \,E,,2F=235 (e=l8,300)] and its infrared spectrum.

The new arninovinylsulfones of this invention are useful as inhibitors for vinyl polymerization, and are especially effective in inhibiting the polymerization of vinyl acetate. They are also useful for crosslinking polyvinyl alcohol and other hydroxylated polymers; one merely heats a mixture of the polymer and sulfone with water and a little mineral acid to obtain crosslinked polymer, probably by acetal formation between the polymer and the sulfonylacetaldehyde formed in situ.

Since obvious modifications in the invention will occur to those skilled in the chemical arts, we propose to be bound solely by the appended claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. The method of synthesizing a compound of the formula wherein R and R are hydrocarbon radicals in which any unsaturation is aromatic and which possess not more than 12 carbon atoms each, which comprises subjecting to about 0.1 to 10,000 watt. -sec./cm. of surface thereof of high energy, ionizing radiation having an energy of at least about 0.1 mev. a precursor of the formula R'SO21FCH=CH2 R and R' being as defined above, thereby rearranging said electrons for seconds under the conditions of Ex;

a e ms precursor, and subsequentlylrecovering the compound of the formula nar-cnqonsoali from irradiated material. V I

2. Themethod of'claim 1 wherein the precursor is a solid;

The method of claim 1 wherein the high energy, ionizingradiation is particle radiation.

4. The method, of claim 1 wherein the high energy, ionizing radiation is, electrons.

. 5 emethod of claim 1 wherein the high-energy, ionizing radiation is electromagnetic radiation.

6- Th meth d f claim 1 h e n the g e y ionizing radiation is X-rays. v

7; The method of synthesizing the amine N-methyl-Z- phenylsulfonylvinylamine which comprises subjecting N- methyl-N-vinylbenzenesulfonamide to about 0.1 to 10,000 watt-sec./cm. of surface thereof of high energy, ionizing [radiation havingan energy of at least about 0.1 mev. and subsequently. recovering said amine from the irradiated material.

8. The method of synthesizing the amine N-methyl-2- p-tolylsulfonylvinylamine which comprises subjecting N- methyl N vinyl p toluenesulfonamide to about 0.1 to 10,000 watt-sec/cm. of surface thereof of high energy, ionizingradiation having an energy of at least about 0.1 mev. and subsequently recovering said amine from the irradiated material.

9. The method of synthesizing the amine N-n-butyl-Z-ptolylsulfonylvinylamine which comprisessubjecting N-nbutyl-Nfvinyl-p-toluenesulfonamide to about 0.1 to 10,000 watt-see/cm. of surface thereof of high energy, ionizing radiation having an energy of at least about 0.1 mev. and subsequently recovering said amine from the irradiated material.

10. The method of synthesizing the amine N-methyl-2- fl-naphthylsulfonylvinylamine which comprisessubjecting N-methyl-N-vinyl-fl-naphthalenesulfonamide to about 01 1* to 10,000 watt-secJcm. of surface thereof of high energy, ionizing radiation having an energy of, at. least about 0.1 mev. and subsequently recoveringsaid amine from the irradiatedmaten'al.

11; The method of synthesizing the amine N-methyl-2 n-butylsulfonylvinylamine which comprises subjecting N- methyl-N-vinylbutanesulfonamide to about 0.1 to 10,000 watt-sec./cm. of surface thereof of high energy, ionizing. radiation having an energy of at least aboutOilmev. andsubsequently recovering said amine from the irradiated material.

12. The method of synthesizing the amine N-methyl-Z- methylsulfonylvinylamine which comprises subjecting N- methyl N-vinylmethanesulfonamide to about 0.1 t o-10,000 watt-sec./cm. of surfacethereof of'high energy, ionizing radiation having an energy of at least about 0.1'mev. and subsequently recovering said amine from the irradiated material. I

13. The method of synthesizing the amine N-methyl-flp-tolylsulfonyl-a-styrylamine which comprises subjecting N-methyl-N-a-styryl-p-toluenesulfonamide to about 0.1 to 10,000 watt-sec./cm. of surface thereof of high energy; ionizing radiation having an energy of at least about 0.1 mev. and subsequently recovering said amine from, the irradiated material.

References Cited in the file of this patent Leandri et aL: Chemical Abstracts, vol. 50,- pp. 221- 222.

Charlesby: Radiation Research, February 1955, pages 96-107.

Tolbert et al.: Radiation Research, September 1955, pages 52-76.

Backer etaL: Rec. Trav. Chim. 72, 833-9 (1953). 

1. THE METHOD OF SYNTHESIZING A COMPOUND OF THE FORMULA 